Table 3.
AAP compared with no AAP for pregnant women with prior VTE* | |||||
---|---|---|---|---|---|
Outcomes | No. of participants (studies) | Certainty in the evidence (GRADE)† | Relative effect, RR (95% CI)‡ | Anticipated absolute effects | |
Risk with no AAP | Risk difference with AAP | ||||
Recurrent major VTE (PE or proximal DVT) | 1519 (11 observational studies)53§|| | ⊕⊕◯◯ Low | 0.39 (0.21-0.72) | 42 per 1000 | 26 fewer per 1000 (33 fewer to 12 fewer) |
Major bleeding, antepartum | 943 (6 RCTs)54¶ | ⊕⊕◯◯ Low# | 0.34 (0.04-3.21) | 6 per 1000 | 4 fewer per 1000 (6 fewer to 14 more) |
Major peripartum bleed | 799 (8 RCTs)54¶ | ⊕⊕◯◯ Low# | 0.82 (0.36-1.86) | 30 per 1000 | 5 fewer per 1000 (19 fewer to 26 more) |
Thrombocytopenia | 945 (8 RCTs)54 | ⊕◯◯◯ Very low#** | 2.37 (0.92-6.11) | 13 per 1000 | 17 more per 1000 (1 fewer to 64 more) |
Bates et al.1 Click here for interactive version of this table: https://gdt.gradepro.org/presentations/#/isof/isof_01618857-BE05-A8CA-8C89-E76E69C5FDD3-1582467465073?_k=w7ov9s.
AAP, antepartum anticoagulant prophylaxis; RR, risk ratio; SoF, summary of findings.
Patient or population: pregnant women with prior VTE. Setting: inpatient or outpatient setting. Intervention: antepartum anticoagulant prophylaxis. Comparison: no antepartum anticoagulant prophylaxis.
GRADE Working Group grades of evidence: high certainty, we are very confident that the true effect lies close to that of the estimate of the effect; moderate certainty, we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different; low certainty, our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect; very low certainty, we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.
The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
Total of 11 studies; 8 had a group that received antepartum prophylaxis; 9 had a group with no antepartum prophylaxis. Of the 11, 7 were retrospective, 4 were prospective (3 were randomized comparisons).
Provoked, unprovoked, or estrogen associated in LMWH.
Most women had a history of placenta-mediated pregnancy complications; none had a history of prior VTE.
The very low event rate leads to uncertainty.
Not a direct outcome of interest, which leads to uncertainty.